Field of the Invention
Exemplary embodiments of the present invention relate to active air flap control, and particularly, to a method for controlling an active air flap and an eco vehicle thereof, which can perform an open/close control of the active air flap based on an aerodynamic force gain portion at a low subzero ambient temperature.
Description of Related Art
In general, even an echo vehicle brings a fuel ratio improvement effect through improvement of an aerodynamic force performance, and thus an active air flap (AAF) is applied thereto.
Since the AAF is controlled to be opened or closed to match the vehicle speed so as to adjust introduction of traveling wind into an engine room, the aerodynamic force performance is improved to lead to the fuel ration improvement effect. In particular, the AAF is divided into an aerodynamic force improvement mode, a cooling-related mode, and a heating-related mode through adjustment of a flap open step between open (completely open (100%)) and close (completely close (0%)) states to maximize the utility thereof.
As an example, the aerodynamic force improvement mode corresponds to a basic function that improves the aerodynamic force performance by adjusting the traveling wind that is introduced into the engine room through adjustment of the flap open step of the AAF to match the vehicle speed. The cooling-related mode corresponds to a function that heightens the heat-exchange performance by introducing the traveling wind to a cooling fan, a condenser, and a radiator through opening of the AAF that matches a cooling load of an air conditioner when an air conditioner system is operated. The heating-related mode corresponds to a function that heightens the heat-exchange performance by introducing the traveling wind to a heat pump through opening of the AAF that matches a heating load of the heat pump when a heat pump heating system is operated.
Accordingly, the AAF brings the aerodynamic force and cooling/heating performance improvement to contribute to even the fuel ratio improvement.
However, the heating-related mode of the AAF has low contribution to optimization of heating power consumption since only component cooling conditions according to the operation of the heat pump heating system are considered in the heating-related mode.
As an example, in the heating-related mode of the AAF, the AAF is kept closed when the heat pump heating system is operated at an ambient temperature below the freezing point (atmospheric condition on which the temperature is about five degrees below the freezing point or lower) at which heat generation of the components is not high, and the AAF is switched over to an open state on the component cooling conditions.
As a result, the opportunity that the heating efficiency of the heat pump heating system is heightened through heat exchange with the subzero ambient temperature is snatched away, and thus the fuel ratio improvement effect according to the reduction of the heating power consumption cannot be expected.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.